Presser wheel



F. F. WITKUS.

PRESSER WHEEL.

APPLICATION FILED APR.,21.1921.

Patented Feb. 21, 1922.

" sewingmachines, perforating machines and U ED STATE.

rnnivx r, wrrxns, ornnwronr, lvnwfnan rsrrinn. I r.

Application filed April 21,

the like, which comprises a wheel mounted on an arm and arranged topress the work against an intermittently driven feed wheel.

Prior tomy invention these presser wheels have, so far as I am aware, been provided with a bearing stud which projects from the rear side ofthe wheel and is j ournaled in the end of the arm by which the wheel is carried. As a rule, the work engaging face of a wheel of this type is formed obliquely to its axis,

7 tically' impossible to remove it.

so that the wheel inclines away from the needle bar and is usually dished or recessed on its side next'the needle bar, so that its face may be pressed against the work as closely as possible to the path of the needle, without interference with the needle bar, or parts carriedthereby. In consequence the direction ofthe force with which the wheel is pressed against the work, or the direction of the perpendicular line to the face of the I wheel, is not only at one side of the bearing of the wheel, but it is also oblique to the axis of the wheel. The combined result causes the stud to be cramped in the bearing to such anektent as to interfere seriously with the free turning of the wheel, particularly as it is pressed against the work with considerable force. Consequently the bearing must be kept well lubricated, to prevent the wheel from dragging on the work. Under these conditions the bearing soon becomes worn, so that parts must be replaced,'and, even when the parts are new and well lubricated, the wheel often does not turn with the freedoin desired. The use of alubricant, at this point, on machines for operating onshoe uppers, is especially objectionable, for, if a drop of oil falls on white or fancy colored upper leather, it is very difficult, or prac- ,To obviate these diflicultles I have proposed to provide a ball-bearing, in lieu of the rnnssnn WHEEL.

Specification of Letters Patent. I

1921. SerialN o 4 3,22a

impractical to vary either the form of the Patentdull b- 21,1922

m? QEFIC. i

wheel, or the formof the arm which sup-"f ports 1t, to a substantial extent, from-those now in use, on account of the spacerequired by the needle bar andthe space require d,"in*

y ces, by'the portion ofthe work" which is fed beneath the hub in which the,

wheel isjournaled, as, for instance, portions in which'laoinghooks are set, and'I have which is permissible, is impractical.

found that a ball bearing of no greater"diameter than the maximum diameterof hub Theobj ects of my invention are'to provide a practically operative form of-ball bearing, for a presser wheel of the above described type, which will be so arranged as to avoid ball race of sufliciently great diameter to op binding in the bearing by the' 'oblique application of forces to the wheel, which has a;

erate satisfactorily, and which is so con- 1 structed that the'presser wheel and' bearing! may be applid tothe wheel-carrying arm of' use without: alteration V these objects in themanner P hereinafter described anda s illustrated in machines now in thereln; r

I accom'phsh the accompanying drawings, in which:

Fig.1. is a: side elevation'of a .presser wheel provided with an embodiment of my invention. x Fig. 2 is a front view of the wheel on an. enlarged scale. a i V Fig. 3 is a longitudinalsectional"view atv line 33 of Fig. l. i Figs. 4c, 5 and 6 are plan and sectional views of a tool which. -I-preferalol'y employ 1 in assembling the bearing.

In Fig. 1 of the drawing the application of the presser wheel to a common'form of reciprocating needle bar sewing machine is indicated,the presserwheel a being shown as pressed down on the work directly above the feed wheel I) and adjacent the needle bar 0, by'an arm d, 1

According tomy invention, and particularlyl as illustrated in FigsJQ and 3, the

wheel a is made in the form of airing, the

work engaging face a: of which is oblique to the plane of the side of-the ring, and tapers from thefront side. The front side of the ring is dished out or recessed tothedepth which wheels ofthis character are usually recessed, so that the thickness at the inner periphery is l'essthan halfthat. at the outer periphery. -The edge,at the inner periphery, is grooved to form a ball race a adapted to receive a set of bearing balls 6, the side edge of the groove, which is in the plane of the rear side, being of less diameter than that at the front side. A bearing member is provided which comprises a screw threaded shaft 7 which extends through the ring a, having a flat circular head f, at one end, the diameter of which is preferably slightly less than the internal diameter of the wheel aperture, and, whenin position, said head will project only slightly beyond the bottom of the recess in the front side of the ring, so that it will lie well out of the path of movement of the needle bar. The edge of the head f is beveled or slightly grooved at its rear side, to provide a circular ball-engaging face, f which is disposed in opposite relation to the rear side portion of the ball race groove a Y A sleeve 9 is threaded on the shaft f and is provided with a flange g, at its end adj acent the rear side of the ring a, said flange being of approximately the same diameter as the head 7, and the edge thereof being slightly beveled, at 9 to provide a circular ball-engaging face in opposite relation to the front sideof the groove (1 the beveled faces 7 and g thusbeing arranged in convergent relation, and, in effect, form, when in adjusted position, the opposite sides of a ball race groove which is opposed to the ball race at The arrangement is, therefore, such that the balls 6 will be held in position by the with relation to the plane of the side of the ring, so that a line from the center of any one of the bearing balls to the middle, transversely, of the groove at will be practically perpendicular to an element of the work-engaging face a.

Consequently, pressure applied to the face a will be received at the middle of the groove a ,'so that there will be no tendency to cramp the bearing, or restrain it from free action, and lubrication will be unnecessary.

The external diameter of the sleeve 9 is such that it will fit closely into the aperture in the end of the arm d, the arm being clamped against the flange g by a nut 7t threaded on the shaft f. In some instances the diameter of the aperture of the arm which supports the wheel is such that the shaft f, instead of the sleeve 9 will fit therein, and in such case the arm would be clamped against the end of the sleeve. The sleeve 9 may, however, be made integral with the arm d, if desired, in which case the diameter in Fig. 6, to hold the same in the desired reelation, so that balls may be placed in position and then the sleeve may be screwed down on the shaft so as to confine the balls in the ball race of the wheel, the shaft f being held from turning, as the sleeve is screwed down, by pins y" mounted in the holder and engaging the head f in apertures formed in the end thereof. 7

I claim: i V

1. A presser wheel for the purpose described, consisting of a ring having its peripheral vface extending convergently from its front side and a ball race groove in its inner periphery arranged correspondingly to said face to receivethe thrust thereon, a series of bearing balls in said groove, a shaft extendingthrough said ring and having a circular head thereon at the front side of said ring, a bearing flange at the rear side of said ring, having a screw-threaded. connection with said shaft, said head and said flange having circular bearing faces arranged for cooperative engagement with said bearing balls, and means for supporting said shaft at the rear side of the wheel.

2. A presser wheel for the purpose de scribed cessed front side and a flat rear side, and having its peripheral, work-engaging face, extending conve-rgently from its front side and a ball race groove formed in its inner peripheral edge in position to directly re ceive the thrust on said work-engaging face, a series of bearing balls in said groove, a shaft extending through said ring and having a circular head thereon at the front side of said ring, a supporting arm and a bearing flange carried by said arm at the rear side of said ringand having a screw-threaded connection with said shaft, said head and said flange having oppositely disposed, circular faces arranged for cooperative engagement with said bearing balls.

3. A presser wheel for the purpose ,de-

consisting of a ring having a rescribed consisting of a ring having an outer peripheral, work-engaging face and an'inner peripheral ball-race groove, a series of bearing balls in said groove, a screw-threaded shaft extending through said ring and having a disk-like head at its front end disposed between the front side of said ring and the plane of the front edge of its face, said head having a circular face arranged to engage said bearing balls oppositely to the rear side of said groove, and a sleeve screwed on said shaft having a circular bearing flange at its end adjacent the rear side of the ring, and said flange having a circular face arranged to engage said balls oppositely to the front side of said groove.

4. A presser wheel for the purpose described consisting of a ring recessed from its front side and having an outer peripheral work-engaging face extending obliquely toward its axis from the front side, the inner peripheral surface of said ring being formed between the bottom of the recess and its rear side and having a ball race groove so formed therein that its rear edge is of a less diameter than its front edge, a shaft extending through said ring and having a head at its front end, said head having a ball race obliquely arranged to engage said balls oppositely to the rear side of said groove, and a sleeve threaded on said shaft and having a circular flange providing a bearing surface arranged to engage the balls oppositely to the front sideof said groove.

5. A presSer wheel for the purpose described consisting of a ring having an outer peripheral work engaging face, with its front side recessed from the front edge of said face, and having-an inner peripheral ball-race groove, a series of bearing balls in said groove, a shaft extending through said ring having a disk-like head at its front end arranged within said recess and rear side of said groove, a bearing member on said shaft arranged for adjustment relatively to said head and having a ball race in opposite relation to the front side of said groove and cooperating with said head to support the balls therein, and supporting means for said shaft at the rear side of said ring.

6. A 'presser wheel for the purpose described consisting of a ring having anouter peripheral work-engaging face, withits front side recessed from the front edge of said face and having an inner peripheral ball-race groove so arranged that its rear edge is of less diameter than its front edge, a series of bearing balls in said groove, a shaft extending through said ring and having a disk-like head thereon at the bottom of said recess, said head having a ball-race In testimony whereof, I have signed my name to this specification.

FRANK F.-WITKUS.

' arranged to face the rear side of said groove, 7 a bearing member adjustably mounted on said shaft and having a ball-race arranged 

